Psychopathy is a personality disorder comprised of a constellation of interpersonal, affective and behavioral characteristics. Individuals with psychopathy are responsible for a disproportionate amount of civil disruption, both criminal and noncriminal. The societal cost of psychopathy, including fiscal and emotional components, rivals those of other major mental illnesses of similar prevalence (~1% general population). However, relative to other major disorders (e.g., schizophrenia), little is known about the etiological bases of the disorder. The most dominant theories in the field posit the psychopath incapable of experiencing negative affect (e.g. fear, anxiety) at levels sufficient to mediate behavioral control or motivate avoidance learning. While a consistent literature has indeed confirmed that psychopaths show reduced reactivity to aversive stimuli, the extent to which psychopaths are truly incapable of normal reactivity remains almost entirely uninvestigated. Given the broad implications of an incapacity model for social, clinical and legal issues, it seems integral that such an assumption receive critical review. As such, the aim of this R21 application is to use physiological and functional magnetic resonance imaging techniques to critically interrogate the assumption that psychopaths are truly incapable of experiencing normal reactivity to aversive stimuli. To this end, we will utilize an emotion- regulation paradigm (Ochsner et al., 2004) capable of evaluating: a) the baseline emotional reactivity, and b) the ability to voluntarily modulate emotional reactivity, within a sample of incarcerated individuals stratified into three groups: those who score high (30 and above;n = 27), moderate (between 20 and 29;n = 27), and low (below 20;n = 27) on the Psychopathy Checklist - Revised (PCL-R;Hare, 1991). Within this emotion- regulation task, participants will be presented with a series of negatively-valent or neutral picture stimuli, and will be instructed, via on-screen instruction, to either "WATCH" the picture (control condition), or to "INCREASE" or "DECREASE" their naturally-occurring emotional response to that picture. The paradigm affords a unique ability to evaluate not just the psychopaths'natural emotional response - as has been undertaken in previous work - but also their ability to increase or decrease that emotional response when that is their primary intention. Current accounts of the disorder must posit an inability to increase or decrease emotion, since they posit broadly limited access to these emotional systems. Indication that psychopaths are capable of voluntarily modulating their emotional reactivity would, however, suggest that they can, at least under certain circumstances, manifest reactivity to aversive stimuli. Such findings could open doors for new diagnostic conceptualizations, new preventative and therapeutic approaches, and new management options within forensic and judicial systems. PUBLIC HEALTH RELEVANCE: Individuals with psychopathy are responsible for a disproportionate amount of civil disruption, both criminal and noncriminal. While current models of the disorder posit an inability to experience negative affect at levels comparable to nonpsychopathic individual, the extent to which this decreased negative affect exists as a core inability remains largely untested. To test this assumption, instead of evaluating psychopaths'natural level of emotional reactivity to aversive stimuli, as has often been undertaken in the past, the present study proposes to use fMRI while explicitly asking psychopaths to maximize and minimize their emotional reactivity. Current accounts of the disorder must posit an inability to increase or decrease emotion, since they posit broadly limited access to these emotional systems. Indication that psychopaths are capable of voluntarily modulating their emotional reactivity would, however, suggest that they can, at least under certain circumstances, manifest reactivity to aversive stimuli. Such findings could open doors for new diagnostic conceptualizations, new preventative and therapeutic approaches, and new management options within forensic and judicial systems.